Reversing mechanism for coke oven battery

ABSTRACT

A coke oven battery reversing mechanism comprises a repeat-cycle timing device that signals the commencement of the sequence of movement of cylinder-piston assemblies to initiate the 1-4,5 reverse, and also the 2,3 reverse of the coke oven battery. Two tandem cylinder-piston assemblies are connected to the actuating rods for the air, waste heat valves and the fuel gas valves, hydraulic power being obtained from an accumulator.

Unite States Patent 3 [1 1 Y Tucker Sept. 3, 1974 REVERSING MECHANISM FOR COKE OVEN BATTERY Linwood G. Tucker, Pittsburgh, Pa.

Koppers Company, Inc., Pittsburgh, Pa.

Filed: Jan. 29, 1973 Appl. No.: 327,595

Related US. Application Data Continuation-in-part of Ser. No. 103,306, Dec. 31, 1970, abandoned, which is a continuation-in-part of Ser. No. 885,678, Dec. 17, 1969, abandoned.

Inventor:

Assignee:

US. Cl; 202/151, 202/141, 202/143,

202/144 Int. Cl. C10b l/06, C10b 21/10 Field of Search 202/151, 139, 141, 143,

References Cited UNITED STATES PATENTS 9/1967 Nestler 202/141 FOREIGN PATENTS OR APPLICATIONS 808,654 2/1959 Great Britain 202/151 4,226,102 12/1967 Japan 202/151 Primary Examiner-Wilbur L. Bascomb, Jr.

Assistant Examiner--D. Sanders Attorney, Agent, or FirmSherman H. Barber; Olin E. Williams; Oscar B. Brumback [5 7 ABSTRACT 7 Claims, 15 Drawing Figures VAL V55 27 dd 35 JAFEH WAVE-{ F DE 12 J'AFETY VAL V55 \ACTUA 708 e005 Fae FUEL 6A5 PATENIEDSEP' 3:974 Y 3933.478

ACTUATO/E e005 CU/V9525 A/E AND WASTE HEAT v44 v5 F019 F EL 5/4 a 5 ACTUATOR 0.05

REVERSING MECHANISM FOR COKE OVEN BATTERY CROSS REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of application Ser. No. 103,306, filed Dec. 31, 1970, and now abandoned which application is a continuation-in-part of application Ser. No. 885,678, filed Dec. 17, 1969, now abandoned.

BACKGROUND OF THE INVENTION 1 The invention relates to coke ovens and, more particularly, to a mechanical mechanism for reversing the flow of air and gas through the flues of the cooling chamber heating walls.

In the operation of a conventional horizontal coke oven battery, it is customary to burn gaseous fuel in one heating flue of a pair of flues during the on-cycle,

and to direct the hot gases of combustion of such gaseous fuel into the other flue during theoff-cycle. Periodically, say every half-hour, the burning of fuel in the on-flues ceases and these flues become the offflues, while the original off-flues become onflues, as gaseous fuel is burned in them.

The change over from on-flues" to off-flues is carried out by reversing certain valves in the basement of the coke oven battery. Reversing may be done manually, by an electro-mechanical mechanism, by an hydro-mechanical means, or by mechanical means associated with a timer mechanism set to induce reversal at prescribed time intervals.

This sequential burning of gaseous fuel in high and low burners in the heating wall flues presents problems in the proper control of the flow of air, waste heat, fuel gas, and decarbonizing air to the coke oven battery flues. In a horizontal coke oven battery, wherein the direction of the flow of air and waste gas is periodically reversed, additional control problems are encountered in the proper sequential operation of the valves controlling the flow of gas and decarbonizing air to the burners.

The control of the flow of fuel gas and the flow of decarbonizing air to the high and the low burners in two groups of flame flues, and the flow of combustion air and waste heat to the same two groups of flame flues increases the number of sequential steps in the operation of a coke oven battery. The steps must be timed to occur in a predetermined sequence, and all of the control components associated with the operation are actuated in response to signals from a central reverse timing mechanism.

As mentioned previously, some reversing mechanisms consist of a large piece of equipment located in the battery control room and associated with such equipment are heavy structural flooring, mechanical connectors such as control rods, chains, sprockets and the like extending between the basement and the control room.

An advantage of an hydraulic reversing machine is that the control room can be located in the most desirable place without regard to a reversing machine.

Because reliability plays such an important part in the consideration of a reversing system for a coke oven battery, it has been customary to select a mechanical system instead of an hydraulic system. But, hydraulic equipment is now available that can be used in a reliable and positive reversing system, and such a system is considerably less costly than a mechanical system in the long run.

The present invention is directed to one such hydraulic reversing system.

For a further understanding of the invention and for other features and advantages thereof, reference may be made to the following description of one embodiment of the invention taken in conjunction with the drawings which illustrate for the purpose of exemplification such embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 illustrates schematically and generally an hydraulic reversing system for a coke oven battery in accordance with the invention;

FIGS. la-lf illustrate the system of FIG. 1 as the system appears in various operative positions;

FIG. 2 illustrates a mechanical detail of the system of FIG. 1;

FIG. 3 illustrates another mechanical detail of the system of FIG. 1;

FIGS. 4-8 illustrate details of a mechanical locking mechanism within the system of FIG. 1; and

FIG. 9 illustrates a simplified wiring diagram of a portion of the system of FIG. 1.

DETAILED DESCRIPTION FIG. 1 illustrates schematically an hydraulic reversing system 11 for the valves of a horizontal coke oven battery. Such a system 11 includes the following principal items of equipment: an accumulator 13; an hydraulic oil supply or sump tank 15; a pump 17 having a suction tube 19 within the tank 15; solenoid actuated valves 21 and 23; a plurality of mechanically actuateable valves 25, 27, 29, 31, 33, and 35; a rich or fuel gas reversing piston-cylinder assembly 37; and an air and waste heat reversing piston-cylinder assembly 39.

The accumulator 13 is of conventional design and is pressurized at all times by the pump 17 which is controlled to cut-in and to cut-out so as to maintain the pressure within the accumulator within a desired range. This is readily accomplished by means of a conventional check valve 18 that is installed in the discharge line from the pump 17, as shown in FIG 1.

The accumulator 13 is fluidly connected by piping 49 to valves 27, 29, 33, and 35 so that one side of a piston in such valves would be kept pressurized at all times, thereby making sure that all of such valves 27, 29, 33, and 35 remain in their desired positions.

In cases of emergency, such as a power failure or the like, it may be necessary to pressurize the accumulator 13 by operating a hand pump (not shown) so that the system can operate for at least one reverse or possibly two reverses. In some applications, a storage battery may provide emergency power to operate a motorized pump (not shown) for pressurizing the accumulator 13.

The reversing system 11 is equally suitable for use in either gun flue type ovens with air decarbonizing, or

and the flues of ovens 2, 3 will be off flues. During the reverse heating, the flues of ovens 2, 3 will be on flues, and the flues of ovens l, 4, and 5 will be off flues.

The reverse is initiated by a timing device 36 (FIG. 9) located preferably in a battery control room. A preferred form of timing device is manufactured and sold by the Eagle Signal Company, Davenport, Iowa. Such a timer 36 is a repeat-cycle timer driven by a synchronous motor and has two timing cams; one cam initiating along the perimeter of the semicircularshaped interlocking plate 95. The locking gate 97 is shown in one operating position in notch 103. The locking gate 97 the 14, 5 reverse, and the othercam initiating the 2,

3 reverse.

As is known, in a reversing operation, the air and waste heat valves are actuated in sequence with the fuel gas valves. Now, in order to place the air and heat waste valves, as well as the'fuel gas valves, in the midposition or neutral position, and in the two extreme open and closed positions, two tandem cylinders, 37, 39, with duel pistons in each cylinder, are employed. FIGS. la-lf illustrate various positions of the system,

shown generally in FIG. 1, during the heating and reversing cycle.

FIG. 2 illustrates the cylinder 37 in which there is a central wall 40 that divides the cylinder interior into two chambers in which pistons 50 and 51 are disposed. Piston 50 is connected to a rod 53 anchored as at 55, and piston 51 is connected to a rod 57 pivotally connected to an arm 59.

The arm 59is fixed to a shaft 61 carrying a cam 63. The cam 63 is disposed to engage and actuate valve 31.

The shaft 61 also carries a pair of spaced apart interlocking plates 65, 67 (FIG. 4) that cooperate with a locking gate 69.,The locking gate 69 is a rectangular shaped bar that is slidable lengthwise and is provided with a notch 71 located so as to allow the interlocking plate 67 to rotate as the shaft 61 rotates when the locking gate 69 isin the operative position shown in FIG.

The interlocking plate 65 is provided with a notch 73 in which the locking gate 69 is disposed, as shown in FIG. 5. r 1 v 1 While not shown, the locking gate 69 moves lengthwise when the air-and waste heat valves move, as described hereinafter. A description of the use of the locking gate 69 is provided herein later on.

Referring again to FIG. 2, the arm 59 is connected to fuel gas valve actuating rods 75, 77 as shown, and the arm 59 is pivotable about the axis of the shaft 61 through an angle of about 90, to the position shown by the dotted outline.

FIG. 3 illustrates the cylinder 39 in which there is a central wall 78 that dividesthe cylinder interior into two chambers in which pistons 79, 81 are disposed. Piston 79 is connected to a rod 83 anchored as at 85, and piston 81 is connected to a rod 87 pivotally connected to another arm 89.

The arm 89 is fixed to a shaft 91 carrying a cam 93; the cam 93 being disposed to engage and actuate valve 25.

The shaft 91 (FIGS. 7, 8) also carries a semicircular shaped interlocking plate95 which cooperates with a rectangular shaped locking gate 97 that is slidable lengthwise and that is provided with a notch 99 located about where shown in FIG. 7.

The interlocking plate 95 is provided with two notches 101, 103 which are disposed about 90 apart also is movable lengthwise when the fuel gas valve rods move and its use is described hereinafter.

Referring again to FIG. 3, the arm 89 is connected to air and waste heat valve actuating rods 105, 107 as shown, and the-arm 89 is pivotable about the axis of the shaft 91 through an angle of about to the position shown by the dotted outline.

Referring now to FIG. 1 and to FIGS. la-l f, a reversing cycle will be described.

It is assumed first that, at the conclusion of a preceding reversing cycle, the fuel gas cylinder 37, and the air and the waste gas cylinder 39 are in their respective positions, as shown in FIG. lf. In the position of FIG. If, the pistons 50 and 51 are at the extreme outer ends of the cylinder 37, which has also moved laterally towards the left by virtue of the fixed anchor 55 which prevents lateral movement of the piston 50 and rod 57. Thus, both the cylinders 37, 39 can and do move laterally, as well as only one piston within each cylinder, since the other piston and piston rod are anchored and cannot move.

When the cylinders 37, 39 move laterally, it will be evident that the respective lever arms 59, 89 pivot about the respective shafts 61, 91, whereby the valve rods 75, 77 and valve rods 105, 107 move to actuate the valves of the battery linked to these rods.

What makes cylinder 37 and piston 50 move is pressurized fluid'entering the cylinder 37 through conduits 109 and 111. The other two conduits 113, of cylinder 37 vent fluid from the cylinder back to the tank 15.

When cylinder 37 is in the position of FIG. 1f, cylinder 39 is also in the position shown in FIG. 1f. In such position, both of the pistons 79, 81, as well as the cylinder 39, are fullyretracted, which is evident when the pistons 79, 81 are closest to the central wall 78.

Cylinder 39 has arrived at this position by introducing fluid under pressure into both chambers of the cylinder 39 through conduits 117, 119. Fluid is also vented from the chambers through conduits 121, 123 back to the tank 15.

'Now, when the reversing timer 36 (FIG. 9) calls for a l4, 5 reverse in the heating cycle, solenoid actuated valve 21 is opened, as shown in FIG. la, so that fluid flows from the accumulator 13 through conduits and ports 115 while fluid vents through conduit 111, flowing back to the sump tank 15.

Thus, at the commencement of a reversing cycle, the pistons 50, 51 and cylinder 37, as well as the pistons 79, 81 and cylinder 39, are positioned as shown in FIG. 1a.

The valves 27, 29, 33, and 35 are normally open and they remain open until pressure in the hydraulic power supply fails. When the hydraulic power fails, valves 27, 29, 33, and 35 close automatically, thus locking all the mechanism in a fixed position. The valves remain in this fixed closed position until power is resumed, whereupon valves 27, 29, 33, and 35 open, and the reversing sequence is restored.

In FIG. la, the fuel gas cylinder 37 is in its neutral position and, while moving to the neutral position, the cam 63 actuates valve 31 thereby causing pressurized fluid to flow into cylinder 39 through conduits 121 and 123, as shown in FIG. 1b.

Pressurizing of conduits 121, 123 and venting conduits 117, 119 results in the movement of the cylinder 39 from the position of FIG. 1a to the position shown in FIG. lb. Piston 37, however, remains in the neutral position, which is the position shown in FIG. 1a.

As the air and waste heat cylinder 39 moves toward its fully extended position shown in FIG. 1b, valve is actuated by cam 93 (FIG. 3).

When valve 25 is actuated, as shown in FIG. 10, pressurized fluid flows from the accumulator 13 through valve 25 in conduit 113 into cylinder 37, and fluid in cylinder 37 vents through conduits 109, 111 back to the sump tank 15.

Wherefore, the piston 51 moves from left to right, as viewed in FIG. 10, thereby pivoting the arm 59 about shaft 61, and the cylinder 37 and pistons 50, 51 assume the fully retracted position shown in FIG. 10.

The 14, 5 reverse is now completed, and the valves remain in the position of FIG. 1c while the coke oven is heated by flues l-4, 5. After a selected heating period, about minutes, the timer 36 indicates a reverse to a 2, 3 heating cycle.

From the position of FIG. 10, with the fuel gas cylinder 37 in the retracted position, the solenoid actuated valve 23 is opened by the timer 36.Pressurized fluid from the accumulator 13 flows into the conduit 111, while fluid within the cylinder 37 is vented through conduit 115 back to the sump tank 15. The piston 50, being anchored as at 55, cannot move; wherefore, the cylinder 37 moves laterally, but the piston 51 does not move relative to the cylinder. Then, the cylinder 37 and pistons 50, 51 assume the position shown in FIG. 1d. As the fuel gas cylinder 37 moves to the position of FIG. 1d, cam 63 on shaft 61 is released; wherefore, the valve 31 assumes the position shown in FIG. 1e.

When the cylinder 39 moves from the position shown in FIG. 1d to that shown in FIG. 1e, fluid under pressure flows in conduits 119, 117 into cylinder 39, and fluid vents therefrom through conduits 121, 123 back to the tank 15. The cylinder 39 then assumes the position shown in FIG. 1e.

As the cylinder 39 moves to the position shown in FIG. 1e, cam 93 releases valve 25 which returns to the position shwn in FIG. 1f.

Fluid under pressure then flows through valve 25 in conduit 109, and fluid vents through conduit 113 back to the sump tank. When pressurized fluid flows through conduit 109 into cylinder 37, piston 51 moves from right to left, as viewed in FIG. 1e, and assumes the position shown in FIG.,1f. When the piston 51 so moves, the piston rod 53 urges the lever 59 to pivot about shaft 61 to actuate the valve rods 75, 77 and, of course, the valves of the battery connected to such rods.

The 2, 3 reverse is now completed, and heating on the 2, 3 cycle continues for a selected period, about 30 minutes.

The position of the valves and cylinders shown in FIG. 1 f is the initial position assumed at the commencement of the description of operation herein. The 1-4, 5 and the 2, 3 reverse cycles are repeated thereafter, as described herein, in accordance with a timed schedule.

While the foregoing describes the basic operation of mechanism in the reversing system 11 of the invention, it is recognized that other operations are carried out simultaneously with some of the sequences described hereinbefore. For example, as soon as the fuel gas cylinder 37 me'ves to the neutral position, as shown in FIG. 1a, valve 31 is actuated by cam 63; and, at the same time, a four-way solenoid valve (not illustrated) is actuated by the fuel gas valve rod to reverse the flow of fluid to conduits 123, 119. Whereupon, the air and waste gas cylinder 39 moves to a neutral position and stops there. The four-way solenoid valve would be electrically connected to another timer (not shown) so that after a predetermined time interval, this other timer would release the four-way solenoid valve to allow the normal flow of fluid to conduits 123, 119 to be resumed. The air and waste heat cylinder would then complete its travel and valve 25 would be actuated by cam 93 as arm 89 rotates, thereby completing the reverse.

In any application, solenoid actuated valves 21 and 23 would be providedwith reset buttons that would allow either solenoid to be energized as desired. This would allow an operator of the coke oven battery to actuate the reversing system from either the I4, 5 or the 2, 3 reverse position.

The reversing system 11 would also be provided with a selector switch, located in the central control room, that would energize either solenoid actuated valve 21 or 23 in the case of an emergency, which would effect moving the fuel gas cylinder 37 to a neutral position. But, in order to prevent the reverse, actuated by pressing the selector switch, from going forward to its full completion, the special four-way valve that reverses the flow of fluid to conduits 121, 123 would be actuated. In such event the timer would be by-passed and the reversing system would remain in neutral until the reset button was pushed a second time. This would then actuate the reverse procedure in the normal manner.

With any reversing mechanism the danger of an explosion or fire is always imminent. Therefore, it is imperative that the actuation of the fuel valves and the air and waste heat valves be carried out sequentially, lest a dangerous condition exist in any flue.

In the sequence described hereinbefore, the fuel gas cylinder 37 can move only in the proper direction when the air and waste heat cylinder 39 is in a proper position. Likewise, the air and waste heat cylinder 39 can move in the proper direction only when the fuel gas cylinder 37 is in a proper position.

FIGS. 4-6 illustrate an interlock system for the fuel gas cylinder. When the arm 59 pivots counterclockwise from the positon shown in FIG. 5 through an angle of about 60, the upper side of the notch 73 engages the locking gate 69, and such locking gate prevents further rotation of the arm 59 until the locking gate 69 moves under the influence of the air and waste heat valve rods. When the notch 71 in the locking gate 69 (FIG. 4) is opposite the interlocking plate 67, the arm 59 is then able to continue its counterclockwise rotation.

Likewise, when the reverse cycle calls for the arm 59 to pivot clockwise from the position described previously, a similar notch 73a (FIG. 6) in the interlockng plate 67 engages the locking gate 69 and prevents the uninterrupted rotation of the arm 59 until the locking gate notch 71 is opposite the interlocking plate 67. Whereupon, complete rotation counterclockwise of the arm 59 is then possible. The locking gate 69 is movable by the air and waste heat valve rods 105, 107.

FIGS. 7 and 8 illustrate a similar interlocking mechanism for controlling the actuation of the air and waste heat valves. Only one locking plate is attached to the shaft 91, but the plate 95 has two notches 101, 103 disposed 90 apart around the perimeter of the locking plate.

The arm 89 can rotate only when the notch 99 (FIG. 7) in the locking gate 97 is opposite the locking plate 95. Otherwise, the locking gate 97, being disposable in the notches 101, 103, prevents rotation of the plate 95 and the arm 89. The locking gate 97 is movable when the rod 75, connected to the fuel gas valves, moves.

It will be noted from FIGS. 7 and 8 that the air and waste heat actuating rods 105, 107 are mechanically interlocked so that the air and waste heat rods can move only if the fuel gas cylinder 37 is in a neutral position with all fuel gas valves closed.

It will be noted from FIGS. 4-6 that the fuelgas cylinder 37 can, at any time, move the fuel gas rods 75, 77 to neutral so as to shut the fuel gas valve, but that the fuel gas rods are mechanically interlocked from completing the stroke and opening the fuel gasvalves unless the air and waste gas cylinder 39 is in its proper position.

While the invention has. been described herein with a certain degree of particularlity, it is understood that the foregoing description has been made as an example only and that the scope of the invention is defined by what is hereinafter claimed.

What is claimed is:

1. In a system whereby reversingthe fuel gas valves and the air and waste heat valves of a coke oven battery effects the reversal of the heating of the battery, the improvement comprising:

a. an actuator rod connected 'to said fuel gas valves;

b. an actuator rod connected to said air and waste heat valves;

c. a source of fluid under pressure;

d. a timer actuating in sequence both a first fluid flow control device and a second fluid flow control device; v

e. conduit means connecting said source of fluid under pressure with both said first and said second fluid control devices;

f. first fluid operated means connected to said fuel gas valve actuatorv rod for opening and closing said fuel gas valves;

g. second fluid operated means connected to said air and waste heat valve actuator rod for opening and closing said air and waste heat valves;

h. a first fluid flow control valve;

i. a second fluid flow control valve;

j. conduit means carrying fluid under pressure to said first fluid flow control valve;

k. conduit means carrying fluid under pressure to said second fluid flow control valve;

1. conduit means carrying fluid from said first flow control valve to said first fluid operated means; m. conduit means carrying fluid from said second fluid flow control valve to said second fluid operated means with saidtimer actuating in sequence,

- said first and second fluid flow control devices so that fluid flows from said source through said first and second fluid control devices, through said fluid flow control valves and into said first and second fluid operated devices, and said actuator rods open said fuel gas valves and said air and waste heat valves in accordance with a preselected schedule that accomplishes reversal of the heating of flues in said coke oven battery;

n. means interlocking the movement of the fuel gas actuator rods and the air and waste heat actuator rod so that each moves only in accordance with a predetermined sequence; and

o. normally open valve means in each one of said conduit means that closes upon receipt of a signal indicating an emergency condition warranting such closing.

2. The invention of claim 1 including:

a. cam means movable with said actuator rods actuates the first and second fluid control valves in accordance with a predetermined sequence.

3. In a system whereby the fuel gas valves and the air and waste heat valves of a coke oven battery effects the reversal of the'heating of the battery, the improvement comprising:

a. a pair of actuator rods connected to the fuel gas valves;

b. a first arm pivotally mounted and connected to said rods;

c. a second pair of actuator rods connected to the air and waste heat valves;

d. a second arm pivotally mounted and connected to said second rods;

e. a source of fluid under pressure;

f. a timing device actuating in sequence both a first and a second fluid flow control device; 7

g. conduit means connecting said source of fluid and said first and second fluid flow control devices;

h. a first fluid actuated means connected to said first arm for pivoting said first arm thereby actuating said fuel gas valves;

i. a second fluid actuated means connected to said second arm for pivoting said second arm and actuating said air and waste heat valves;

j. a first flow control valve;

k. a second flow control valve;

1. conduit means connecting said first fluid flow control device to said first fluid actuated means;

m. conduit means connecting said second fluid flow ontrol device to said second fluid actuated means;

n. conduit means connecting said first control valve and said second control valve; v I

o. first can means actuated by said first arm for actuating said second flow control valve;

p. second cam means actuated by said second arm for actuating said first flow control valve, whereby in sequence said timer actuates said first fluid control device and fluid flows through said first flow control device into said first fluid actuated means and said fuel gas valve actuator rods move to reverse the position of said valves, and in sequence said fluid flows into said second fluid actuated means and said air and waste heat valve actuator rods move to reverse the position of said valves;

normally open valve means in said conduit means connecting said first and second flow control devices with said first and second fluid actuated means, said valve means being closable automatically in response to a signal indicating an emergency situation in said system;

r. said first and said second fluid actuated means each include a cylinder wherein there are two pistons a. said interlocking means is actuated by movement of said air and waste heat valve actuating rods.

6. The invention of claim 3 including:

a. interlocking means for preventing the inadvertent actuation of said air and waste heat valves until said fuel gas valves are in a preselected proper position.

7. The invention of claim 6 wherein: a. said interlocking means is actuated by movement of said fuel gas valve actuating rods. 

1. In a system whereby reversing the fuel gas valves and the air and waste heat valves of a coke oven battery effects the reversal of the heating of the battery, the improvement comprising: a. an actuator rod connected to said fuel gas valves; b. an actuator rod connected to said air and waste heat valves; c. a source of fluid under pressure; d. a timer actuating in sequence both a first fluid flow control device and a second fluid flow control device; e. conduit means connecting said source of fluid under pressure with both said first and said second fluid control devices; f. first fluid operated means connected to said fuel gas valve actuator rod for opening and closing said fuel gas valves; g. second fluid operated means connected to said air and waste heat valve actuator rod for opening and closing said air and waste heat valves; h. a first fluid flow control valve; i. a second fluid flow control valve; j. conduit means carrying fluid under pressure to said first fluid flow control valve; k. conduit means carrying fluid under pressure to said second fluid flow control valve; l. conduit means carrying fluid from said first flow control valve to said first fluid operated means; m. conduit means carrying fluid from said second fluid flow control valve to said second fluid operated means with said timer actuating in sequence, said first and second fluid flow control deVices so that fluid flows from said source through said first and second fluid control devices, through said fluid flow control valves and into said first and second fluid operated devices, and said actuator rods open said fuel gas valves and said air and waste heat valves in accordance with a preselected schedule that accomplishes reversal of the heating of flues in said coke oven battery; n. means interlocking the movement of the fuel gas actuator rods and the air and waste heat actuator rod so that each moves only in accordance with a predetermined sequence; and o. normally open valve means in each one of said conduit means that closes upon receipt of a signal indicating an emergency condition warranting such closing.
 2. The invention of claim 1 including: a. cam means movable with said actuator rods actuates the first and second fluid control valves in accordance with a predetermined sequence.
 3. In a system whereby the fuel gas valves and the air and waste heat valves of a coke oven battery effects the reversal of the heating of the battery, the improvement comprising: a. a pair of actuator rods connected to the fuel gas valves; b. a first arm pivotally mounted and connected to said rods; c. a second pair of actuator rods connected to the air and waste heat valves; d. a second arm pivotally mounted and connected to said second rods; e. a source of fluid under pressure; f. a timing device actuating in sequence both a first and a second fluid flow control device; g. conduit means connecting said source of fluid and said first and second fluid flow control devices; h. a first fluid actuated means connected to said first arm for pivoting said first arm thereby actuating said fuel gas valves; i. a second fluid actuated means connected to said second arm for pivoting said second arm and actuating said air and waste heat valves; j. a first flow control valve; k. a second flow control valve; l. conduit means connecting said first fluid flow control device to said first fluid actuated means; m. conduit means connecting said second fluid flow ontrol device to said second fluid actuated means; n. conduit means connecting said first control valve and said second control valve; o. first can means actuated by said first arm for actuating said second flow control valve; p. second cam means actuated by said second arm for actuating said first flow control valve, whereby in sequence said timer actuates said first fluid control device and fluid flows through said first flow control device into said first fluid actuated means and said fuel gas valve actuator rods move to reverse the position of said valves, and in sequence said fluid flows into said second fluid actuated means and said air and waste heat valve actuator rods move to reverse the position of said valves; q. normally open valve means in said conduit means connecting said first and second flow control devices with said first and second fluid actuated means, said valve means being closable automatically in response to a signal indicating an emergency situation in said system; r. said first and said second fluid actuated means each include a cylinder wherein there are two pistons with a wall between the pistons subdividing the cylinder into two chambers, and wherein; s. one piston is secured to a piston rod that is fixed, whereby only the other piston and the cylinder are movable.
 4. The invention of claim 3 including: a. interlocking means for preventing the inadvertent actuation of said fuel gas valves until said air and waste heat valve are in a preselected proper position.
 5. The invention of claim 4 wherein: a. said interlocking means is actuated by movement of said air and waste heat valve actuating rods.
 6. The invention of claim 3 including: a. interlocking means for preventing the inadvertent actuation of said air and waste heat valves until said fuel gas valves are in a preselected proper position.
 7. The invention of claim 6 wherein: a. said interlocking means is actuated by movement of said fuel gas valve actuating rods. 